Statistical Analysis of Structural Transitions in Small Systems

We discuss general thermodynamic properties of molecular structure formation processes like protein folding by means of simplified, coarse-grained models. The conformational transitions accompanying these processes exhibit similarities to thermodynamic phase transitions, but also significant differences as the systems that we investigate here are very small. The usefulness of a microcanonical statistical analysis of these transitions in comparison with a canonical interpretation is emphasized. The results are obtained by employing sophisticated generalized-ensemble Markov-chain Monte Carlo methodologies.